Fig. 5: Effects of gyrase mutations on tetA-mediated counter-silencing.

a Representative flow cytometry profiles from cultures of strains MA14805 (P^tettetA-T^hisL-SGS gyrA⁺) and MA14804 (P^tettetA-T^hisL-SGS gyrA208) grown to early stationary phase in the presence or absence of AHTc. The two strains are isogenic siblings from a transductional cross in which gyrA208 was introduced in the P^tettetA-T^hisL-SGS hilA-GFP^SF background using a gyrA-linked cat insertion. b Percentage of cells expressing hilA-GFP^SF in n = 3 independent repeats of the analysis in (a). c Representative flow cytometry profiles from cultures of strains MA14813 (P^tettetA-T^hisL-SGS gyrB⁺) and MA14812 (P^tettetA-T^hisL-SGS gyrB1820) grown as in (a). The two strains are isogenic siblings from a transductional cross in which gyrB1820 was introduced in the P^tettetA-T^hisL-SGS hilA-GFP^SF background using a gyrB-linked cat insertion. d Maximal GFP fluorescence values measured in gyrB1820 mutant cells grown as in (a) in n = 4 independent experiments. Data in (b, d) are presented as mean values ± SD. Statistical significance was determined by RM one-way ANOVA with Šidák’s multiple comparisons test in (b) (adjusted P value for the gyrA⁺/gyrA208 comparison = 0.0188) and the unpaired two-tailed Student’s t test in (d) (P = 0.0006); (*P ≤ 0.05; ***P ≤ 0.001). Source data are provided as a Source Data file.